This invention relates to an apparatus for positioning slide forks provided on stacker cranes used for auto warehouses, etc. relative to load racks. A positioning means for vehicles is disclosed in U.S. Pat. Nos. 3,123,240 and 4,109,804.
In the case of conventional stacker cranes, slide forks by which loads are delivered to or from load racks have been fixed onto stacker cranes (referred to hereinafter as cranes). On the other hand, in recent years, rationalization of machining process has been advanced, and a system of delivering works or the like from cranes directly to machine tools or auto-conveyors has been developed. In the case of such a system, the precision of positioning at the time of the delivery is very important since it determines the precision of the subsequent process. Thus, even when works, etc. are transferred from load racks onto slide forks, a problem is raised as to how to transfer works, etc. to a definite position on the slide forks. However, in the case where slide forks are conventionally fixed onto cranes, one cannot help positioning cranes relative to load racks. But it is extremely difficult to position large, heavy weight cranes at a high precision and rapidly.
In view of this fact, the object of the present invention is to provide an apparatus wherein light weight slide forks are made freely movable on cranes and directly positioned relative to load racks to thereby improve the precision and efficiency of the positioning.